This page includes simple formula for the calculation of the maximum stress and deflection for thin flat
plates under a variety of support and loading conditons. The equations are only valid if the deflection is small
compared to the plate thickness. The plates are all assumed to be steel with a poisson's ratio of 0,3.
The equations are also only reasonably accurate if the thickness is less than 10% of the
diameter. The results can be used for initial estimates - For more accurate results it is recommended that
quality reference books are used i.e "Roark's Formulas for Stress and Strain". I also recommend Mitcalc.com see link 1
below - a suite of calculators based on Excel.

The loading scenario for the simply supported rectangular plates assume that the upper edges of the loaded surface are restrained from lifting
such that all of the edges are in contact during the the loading condition.

Note: I have checked the results from some of the equations against results using Mitcalc.com . The deflections and stresses resulting
are generally resonably accurate. I have checked my results against Roark and they seem to be OK.
I would recommend that for more comprehensive calculations including greater detail with more accuracy standard reference texts are used e.g Roarks book.

I have created a excelcalcs based spreadsheet for convenient access to all of the equations on this page. This is located at
ExcelCalcs.com calculation Plates
There are also other detailed calcs/ tables/ graphs for a number of different plate configurations on the excelcalcs site ref.
Excelcalcs Plates